English to Polish Marketing IT (Information Technology)

Umowa dotyczy nowych usług marketingowych (platformy DSP, real time bidding) i pojawiają się takie fragmenty:
The XXX hereby appoints the ZZZ as supplier and advisor for securing inventory within ad exchanges and other media sources via DSP.
In order to perform the Services, the ZZZ will secure inventory through XXXX in respect of the Services listed below.

I jeszcze samo inventory w takim kontekście:
The ZZZ offers to its clients real time bidding and optimization of display, video, and other inventory.

Trochę nie mam pojęcia, o co chodzi z tym "inventory", będę wdzięczna za każdy trop.